text: Hyrax midden structures and accumulation rates can vary considerably based on the relative proportion of their two primary components, pellets and hyraceum, which is determined by the architecture of the site itself. Depending on the shape and irregularities of the floor of the site in question, pellets are likely to either accumulate (in concave structures) or roll away (in convex or inclined structures). Whereas hyrax urine will deposit only a very thin film of hyraceum after evaporation, pellets are usually 0.5-1 cm in diameter, and thereby accumulate much more quickly., with deep piles accumulating perhaps within just a few years, or even months. Compared to this, we have observed that middens composed primarily of hyraceum accumulate much more slowly; generally between ~5 and >1000 years/mm. The rate of hyraceum accumulation depends on the morphology of the midden, the architecture of the site, as well as presumably the size of the hyrax colony, and as such net rates can be highly variable